If an employee refuses to sign the notice of the preliminary interview, does that necessarily render the procedure invalid?

Mr. [V] was hired as a heavy-duty truck driver on March 30, 2015, by Mr. [S], who operated a sole proprietorship engaged in the decontamination and recycling of damaged vehicles, the rights to which were subsequently acquired by [S] Autos.

The employee was terminated for cause on February 23, 2016.

Mr. [V], who had less than two years of seniority at the time of his dismissal, contends that he was not properly summoned to the preliminary interview, which deprived him of his right to be assisted during that interview, in violation of the provisions of Article L. 1232-4 of the Labor Code.